const months = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec']

const timeToEng = function(time) {
	const date = new Date(time)
	return months[date.getMonth()]
}
// 输入time为时间戳,add表示加减天数, 默认为0
const timeFormat = function(time, fmt, add = 0) {
	if (time === undefined || time === null) {
		return '无'
	}
	var date = new Date()
	date.setTime(new Date(Number(time)).getTime() + 1000 * 60 * 60 * 24 * add)
	var o = {
		'M+': date.getMonth() + 1, // 月份
		'd+': date.getDate(), // 日
		'h+': date.getHours(), // 小时
		'm+': date.getMinutes(), // 分
		's+': date.getSeconds(), // 秒
		'q+': Math.floor((date.getMonth() + 3) / 3), // 季度
		'S': date.getMilliseconds() // 毫秒
	}
	if (/(y+)/.test(fmt)) {
		fmt = fmt.replace(RegExp.$1, (date.getFullYear() + '').substr(4 - RegExp.$1.length))
	}
	for (const k in o) {
		if (new RegExp('(' + k + ')').test(fmt)) {
			fmt = fmt.replace(RegExp.$1, (RegExp.$1.length === 1) ? (o[k]) : (('00' + o[k]).substr(('' + o[k])
				.length)))
		}
	}
	return fmt
}

// 获取当月开始结束日期 cch
const getCurrentMonthDay = () => {
	const now = new Date()
	const yindex = now.getFullYear() - 1990
	const mindex = now.getMonth()
	const day = now.getDate() - 1
	return [
		[yindex, mindex, 0],
		[yindex, mindex, day]
	]
}
// 当前日期
const parseTime = function parseTime(time, cFormat) {
	const format = cFormat || 'y/m/d h:i:s'
	let date
	if (typeof time === 'object') {
		date = time
	} else {
		if (('' + time).length === 10) time = parseInt(time) * 1000
		date = new Date(time)
	}
	const formatObj = {
		y: date.getFullYear(),
		m: date.getMonth() + 1,
		d: date.getDate(),
		h: date.getHours(),
		i: date.getMinutes(),
		s: date.getSeconds(),
		a: date.getDay()
	}
	const time_str = format.replace(/(y|m|d|h|i|s|a)+/g, (result, key) => {
		let value = formatObj[key]
		// Note: getDay() returns 0 on Sunday
		if (key === 'a') {
			return ['日', '一', '二', '三', '四', '五', '六'][value]
		}
		if (result.length > 0 && value < 10) {
			value = '0' + value
		}
		return value || 0
	})
	return time_str
}
// 获取现在日期指定多少天前
const getBeforeDate = function getBeforeDate(n) {
	var n = n;
	var d = new Date();
	var year = d.getFullYear();
	var mon = d.getMonth() + 1;
	var day = d.getDate();
	if (day <= n) {
		if (mon > 1) {
			mon = mon - 1;
		} else {
			year = year - 1;
			mon = 12;
		}
	}
	d.setDate(d.getDate() - n);
	year = d.getFullYear();
	mon = d.getMonth() + 1;
	day = d.getDate();
	return year + "-" + (mon < 10 ? ('0' + mon) : mon) + "-" + (day < 10 ? ('0' + day) : day);
}

const dateDiff = function dateDiff(sDate1, sDate2) { //sDate1和sDate2是"2002-12-18"格式
	var aDate, oDate1, oDate2, iDays;
	aDate = sDate1.split("-");
	oDate1 = new Date(aDate[0], aDate[1] - 1, aDate[2]);
	aDate = sDate2.split("-");
	oDate2 = new Date(aDate[0], aDate[1] - 1, aDate[2]);
	iDays = parseInt(Math.abs(oDate1 - oDate2) / 1000 / 60 / 60 / 24);
	if ((oDate1 - oDate2) < 0) {
		return -iDays;
	}
	return iDays;
}

const getDateTime = function getDateTime(time) {
	let date = new Date(time);
	let year = date.getFullYear();
	let month = date.getMonth() + 1;
	let day = date.getDate();
	month = month > 9 ? month : '0' + month;;
	day = day > 9 ? day : '0' + day;
	return `${year}-${month}-${day}`;
}

export {
	timeToEng,
	timeFormat,
	getDateTime,
	getCurrentMonthDay,
	parseTime,
	getBeforeDate,
	dateDiff
}
